Plastic closure



FIG. 1 is a top perspective view of the plastic closure;

FIG. 2 is a side elevational view of the plastic closure, the opposing side elevational view and the two end elevational views being identical thereto; and,

FIG. 3 is a top plan view of the plastic closure, the bottom view forms no part of the claimed design. 

The ornamental design for a plastic closure, as shown and described. 